When standing in line or waiting in traffic, for example, all the people who are waiting are equally as worthy to get what they wait for or to arrive at their destinations. I know, however, only my own thoughts and am intimately aware of only my own needs, which naturally incline me to put myself first. The result is frustration that I'm not first, and this strongly tempts me to be impatient.
A second reason why patience is such a challenge is that none of us struggle with precisely the same temptations as do other people. Nor are our particular strengths and weaknesses the same as those of others. One person is even-tempered and can't understand why her friend flies off the handle at times. But the person with the bad temper cannot understand how her even-keeled friend can be habitually late to meetings. And both of them get annoyed at a third friend's tendency to overeat.
This is, of course, another aspect of the egocentric predicament. None of these friends knows what it's like to have the others' peculiar weaknesses. Nor does each comprehend how much effort the others are exerting in order to be as moral as they are, for it's not immediately apparent how hard the others work to control themselves. The result, again, is the temptation to become impatient with them.
Why is patience toward God so difficult? The explanation boils down to, again, our tendency to see things only from our own point of view. Further reasons compound the difficulty of waiting upon God. For one thing, patience with God involves faith, and to exercise faith is to surrender final control of one's life. To lack faith is to give in to one's desire for control. So our patience with God will only be as strong as our ability to overcome this desire and surrender every aspect of our lives.
Patience with God is a challenge, too, because sometimes it's not at all clear whether it is God we're waiting for or whether we should even wait on him at all. The unemployed person may wonder, "Have I waited too long rather than taking more action?" The person desiring a spouse might second-guess herself, "Have I taken the right social steps?" And the childless couple might wonder, "Should we pursue clinical help in order to conceive?" Sometimes it's simply unclear whether God wants us to wait or take another course of action.
Finally, and most difficult of all, there's no guarantee that God will, indeed, act to satisfy our desires. Most situations that demand patience aren't in regard to specific promises of God. Although he has told us he will meet all our needs, he hasn't guaranteed that all of our desires, even significant ones, will be satisfied. Here, someone might note the biblical promise that if you "delight yourself in the Lord … he will give you the desires of your heart" (Ps. 37:4). This, however, is not a promise that all of our present desires will be fulfilled the way we want them to be. Sometimes they are, but often God keeps this promise by adjusting our desires to bring them into line with his will. If this is disappointing, keep in mind that even if God does change our desires, they are still our sincere desires!